The present invention relates to radio data communication systems and, more particularly, to a method of reconnecting a line after occurrence of a disconnection or an open line due to radio wave interruption during communication.
With recent development of communication middle wear and the like, it has become possible to cover the reliability concerning the occurrence of open lines due to radio wave interruption during communication in radio data communication by confirming the transmission with buffers provided on both the data transmitting and receiving sides. However, the operation of re-raising (i.e., reconnecting) an open line should be performed on the basis of circumstance judgment made by a person with experience.
When an open line occurs due to radio wave interruption during communication in a bad radio circumstance condition place, it is highly possible to fail in connection in a reconnection trial or, although connection may be obtained, an open line will occur again. In such cases, it is necessary to postpone the reconnection trial until the condition becomes good. The operation of reconnection has many problems. It must be manually performed by a person whenever a disconnection of a line or an open line occurs, regardless of whether the data communication will fail, and accordingly, multiple attempts at reconnection may be required. Automation of the reconnection process thus has been demanded.
The present invention was made in view of the above problem, and its object is to provide system or method for automatically making the reconnection of an open line occurring during communication in mobile communication and also making condition judgment for the reconnection.
The present invention features adopting a system in radio data communication, in which radio terminals statistically learn the circumstances of the radio communication line and makes an automatic call when predetermined conditions are met.
According to an aspect of the present invention, there is provided an automatic call making system comprising: a plurality of base stations each having a specific identification number and having a cellular structure for transmitting signal in a waiting control channel; and a radio terminal having means for receiving radio waves transmitted from the base stations, a clock, an input electric field intensity level detecting means or a BER detecting means and a means for detecting a base station identification signal, and having a function of tentatively storing data to be transmitted and a function of resuming and continuing communication by automatically doing a line connecting process (call making) when stored data is present; wherein the terminal measures a receiving time, during which stable radio wave reception is possible, for each base station identification signal, stores these times as statistically stable receiving times, and makes a call to a base station on the basis of the pertinent statistically stable receiving time.
The statistically stable receiving times are obtained by measuring a time, during which the average input electric field intensity level is above a predetermined value, or a time, the average value of the BERs is below a predetermined value.
The terminal makes a call when it receives a radio wave from a base station, in which the statistically stable receiving time is above a predetermined constant time.
The terminal makes a call when it receives a radio wave from a base station, in which the statistically stable receiving time is above a predetermined constant time, in a statistically absolute receiving time.
The terminal makes a call when it receives a radio wave from a statistically receivable base station in an intentionally set absolute time around the same time.
For making a call the terminal subtracts a time having been present in a time range of a base station identification signal being received from the pertinent statistically stable receiving time, and postpones the call making when the difference is below a prescribed value, while making a call when the difference is above the prescribed value.
According to another aspect of the present invention, there is provided an automatic call making system comprising: a plurality of base stations each having a specific identification number and having a cellular structure for transmitting signal in a waiting control channel; and a radio terminal having means for receiving radio waves transmitted from the base stations, a clock, an input electric field intensity level detecting means or a BER detecting means and a means for detecting a base station identification signal, and having a function of tentatively storing data to be transmitted and a function of resuming and continuing communication by automatically doing a line connecting process (call making) when stored data is present; wherein the terminal measures a receiving time, during which stable radio wave reception is possible, for each base station identification signal, stores these times as statistically stable receiving times, stores receiving order combinations of the base stations of the statistically stable receiving times from the absolute times for a base station in which the statistically stable receiving times is above a predetermined time, and when an open line takes place or a line is disconnected during communication in the area in charge of any of the above base stations, waits the reception of a radio wave from the base station to be subsequently received in the basis of the receiving order combinations, and upon reception of the radio wave makes a call to a pertinent base station.
According to other aspect of the present invention there is provided an automatic call making system comprising: a plurality of base stations each having a specific identification number and having a cellular structure for transmitting signal in a waiting control channel; and a radio terminal having means for receiving radio waves transmitted from the base stations, a clock, an input electric field intensity level detecting means or a BER detecting means and a means for detecting a base station identification signal, and having a function of tentatively storing data to be transmitted and a function of resuming and continuing communication by automatically doing a line connecting process (call making) when stored data is present; wherein the terminal receives a waiting control channel which is always transmitted by the base stations, and makes a call when the average value of the input electric field intensity levels exceeds a predetermined value or when the average value of the short times BERs is below a predetermined value and also the degree of separation from the average value of the instantaneous electric field intensity levels in the average time is below a predetermined value.
The terminal postpones the call making for predetermined time when the input electric field intensity level becomes below a predetermined value.
According to still other aspect of the present invention there is provided, in a radio communication system comprising plurality of base stations each having a cellular structure of transmitting a specific identification signal in a waiting control channel; a radio terminal having a means for receiving radio waves transmitted from the base stations and a means for detecting the base station identification signal, and having a function of tentatively storing data to be transmitted and a function of automatically doing a line connecting process (call making) for resuming and continuing communication if stored data is present; and a switching system for doing a hand-over process that the terminal; successively receives radio waves from the plurality of base stations and switching the communication line to the base station of the best electric field intensity; an automatic call making system, in which the switching system predicts the route of the terminal, and when the terminal is handed over from a first base station to a second base station having a transmission/reception allowable time shorter than a predetermined time, forcively disconnects the communication of the second base station with the terminal, in the communication disconnecting process the terminal provides to the terminal a third base station identification signal allowing transmission/reception for more than predetermined time, and when receiving the third identification signal the terminal makes a call to the third base station for resuming the communication.
According to further aspect of the present invention there is provided a mobile radio terminal comprising a means for receiving radio waves from a plurality of base stations each having a cellular structure of transmitting a specific identification signal in a waiting control channel, a clock, an input electric field intensity level detecting means or a BER detecting means and a means for detecting base station identification signals of the plurality of base stations, and having a function of tentatively storing transmitted data and a function of resuming and continuing communication by automatically doing a line connecting process (call making when stored data is present, wherein the terminal includes a means for measuring a stably receivable time for each base station identification signal and storing the measured times as statistically stable receiving times, and a means for making a call to the patient base station on the basis of the statistically stable receiving times.
In the present invention, the terminal estimates a communication time from the quantity of data to be transmitted to make it possible to select the time and place of re-connection trial start with reference to a statistically stable reception time of a base station capable of effecting the transmission and reception.
In the different embodiment of the present invention features that a switching system for controlling base stations forecasts the circumstances of radio communication lines of radio terminals and advises the radio terminal of the identification number of a base station which satisfies the predetermined conditions, and each radio terminal makes an automatic call to the contacted base station from which the identification number of the base station.